DESCRIPTION (Adapted from the application): Osteoporosis and Paget's disease are two of the most widespread disorders of bone disease. Osteoporosis affects more than 24 million people in the United States and its victims now cost an estimated $7 to $10 billion per year. Osteoporosis contributes to over 1.3 million fractures per year. Paget's disease progresses slowly and can cause pain, osteolytic lesions, and gross deformities of bone structure. Osteoporosis and Paget's disease involve an imbalance between bone growth and resorption; both diseases can be treated effectively with polypeptide hormones known as calcitonins. Concern about the side effects of steroid hormones for the treatment of osteoporosis is forcing clinicians to prescribe calcitonin in Europe and now in the United States. The polypeptide is administered by daily subcutaneous or intermuscular injection. This practice is poorly accepted by patients because of inconvenience and high incidence of adverse reactions. A monthly sustained injection of salmon calcitonin could provide a much more attractive combination of efficiency and convenience than either of the existing methods of administration. PROPOSED COMMERCIAL APPLICATION: Potential commercial application not available.